diff --git a/config.def.h b/config.def.h
index fba3aa1..527650f 100644
--- a/config.def.h
+++ b/config.def.h
@@ -51,7 +51,8 @@ static const Layout layouts[] = {
 #define SHCMD(cmd) { .v = (const char*[]){ "/bin/sh", "-c", cmd, NULL } }
 
 /* commands */
-static const char *dmenucmd[] = { "dmenu_run", "-fn", dmenufont, "-nb", col_gray1, "-nf", col_gray3, "-sb", col_cyan, "-sf", col_gray4, NULL };
+static char dmenumon[2] = "0"; /* component of dmenucmd, manipulated in spawn() */
+static const char *dmenucmd[] = { "dmenu_run", "-m", dmenumon, "-fn", dmenufont, "-nb", col_gray1, "-nf", col_gray3, "-sb", col_cyan, "-sf", col_gray4, NULL };
 static const char *termcmd[]  = { "st", NULL };
 
 static const Key keys[] = {
diff --git a/config.mk b/config.mk
index e761a6e..19e4ddc 100644
--- a/config.mk
+++ b/config.mk
@@ -22,7 +22,7 @@ INCS = -I${X11INC} `pkg-config --cflags cairo pango pangocairo`
 LIBS = -L${X11LIB} -lX11 ${XINERAMALIBS} `pkg-config --libs cairo pango pangocairo` -lXrender
 
 # flags
-CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_POSIX_C_SOURCE=200809L -DVERSION=\"${VERSION}\" ${XINERAMAFLAGS}
+CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=700L -DVERSION=\"${VERSION}\" ${XINERAMAFLAGS}
 #CFLAGS   = -g -std=c99 -pedantic -Wall -O0 ${INCS} ${CPPFLAGS}
 CFLAGS   = -std=c99 -pedantic -Wall -Wno-deprecated-declarations -O0 ${INCS} ${CPPFLAGS}
 LDFLAGS  = ${LIBS}
diff --git a/dwm.c b/dwm.c
index 033ed3e..e064911 100644
--- a/dwm.c
+++ b/dwm.c
@@ -206,7 +206,6 @@ static void setmfact(const Arg *arg);
 static void setup(void);
 static void seturgent(Client *c, int urg);
 static void showhide(Client *c);
-static void sigchld(int unused);
 static void spawn(const Arg *arg);
 static void tag(const Arg *arg);
 static void tagmon(const Arg *arg);
@@ -988,16 +987,26 @@ grabkeys(void)
 {
 	updatenumlockmask();
 	{
-		unsigned int i, j;
+		unsigned int i, j, k;
 		unsigned int modifiers[] = { 0, LockMask, numlockmask, numlockmask|LockMask };
-		KeyCode code;
+		int start, end, skip;
+		KeySym *syms;
 
 		XUngrabKey(dpy, AnyKey, AnyModifier, root);
-		for (i = 0; i < LENGTH(keys); i++)
-			if ((code = XKeysymToKeycode(dpy, keys[i].keysym)))
-				for (j = 0; j < LENGTH(modifiers); j++)
-					XGrabKey(dpy, code, keys[i].mod | modifiers[j], root,
-						True, GrabModeAsync, GrabModeAsync);
+		XDisplayKeycodes(dpy, &start, &end);
+		syms = XGetKeyboardMapping(dpy, start, end - start + 1, &skip);
+		if (!syms)
+			return;
+		for (k = start; k <= end; k++)
+			for (i = 0; i < LENGTH(keys); i++)
+				/* skip modifier codes, we do that ourselves */
+				if (keys[i].keysym == syms[(k - start) * skip])
+					for (j = 0; j < LENGTH(modifiers); j++)
+						XGrabKey(dpy, k,
+							 keys[i].mod | modifiers[j],
+							 root, True,
+							 GrabModeAsync, GrabModeAsync);
+		XFree(syms);
 	}
 }
 
@@ -1583,9 +1592,16 @@ setup(void)
 {
 	XSetWindowAttributes wa;
 	Atom utf8string;
+	struct sigaction sa;
 
-	/* clean up any zombies immediately */
-	sigchld(0);
+	/* do not transform children into zombies when they terminate */
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_NOCLDSTOP | SA_NOCLDWAIT | SA_RESTART;
+	sa.sa_handler = SIG_IGN;
+	sigaction(SIGCHLD, &sa, NULL);
+
+	/* clean up any zombies (inherited from .xinitrc etc) immediately */
+	while (waitpid(-1, NULL, WNOHANG) > 0);
 
 	/* init screen */
 	screen = DefaultScreen(dpy);
@@ -1675,21 +1691,23 @@ showhide(Client *c)
 	}
 }
 
-void
-sigchld(int unused)
-{
-	if (signal(SIGCHLD, sigchld) == SIG_ERR)
-		die("can't install SIGCHLD handler:");
-	while (0 < waitpid(-1, NULL, WNOHANG));
-}
-
 void
 spawn(const Arg *arg)
 {
+	struct sigaction sa;
+
+	if (arg->v == dmenucmd)
+		dmenumon[0] = '0' + selmon->num;
 	if (fork() == 0) {
 		if (dpy)
 			close(ConnectionNumber(dpy));
 		setsid();
+
+		sigemptyset(&sa.sa_mask);
+		sa.sa_flags = 0;
+		sa.sa_handler = SIG_DFL;
+		sigaction(SIGCHLD, &sa, NULL);
+
 		execvp(((char **)arg->v)[0], (char **)arg->v);
 		die("dwm: execvp '%s' failed:", ((char **)arg->v)[0]);
 	}